Fuse protector device



NOV, 6, 1945. 1 s CURTlsS 2,388,309

FUSE PROTECTOR DEVICE Filed oct. 23,1942

INVENTR= JOHN scuRTlss BY ATT RNE t Patented Nov. 6, 1945 FUSE PROTECTOR DEVICE i John S. Curtiss, El Paso, Tex. Application October 23, 1942, Serial No.7463, 034

7 Claims.

The invention relates to the art of connecting fulminating caps, such as are used in blasting and various military operations, to fuses leading to the cap and ignited at a point remote from the cap.

To provide for aready attachment of the fuse to the cap and to aord protection for the joint between the fuse and the cap and to prevent the admission of moisture to the cap, it is a practice to apply a short length of rubber tubing over the adjacent portions of the fuse and capiv Patents Nos. 636,919, issued November 14, 1889, and 931,454, issued August 17, 1909, to William E. Miller, disclose protectors of the type referred to and devices-facilitating the handling of the protectors at the time of their application tothe cap and fuse. The devices disclosed in the abovementioned patents comprise sticks upon which a plurality of the protectors are rolled in doughnut form. The end of the stick is arranged to be inserted into a detonator cap so that one of the fuse protectors may be rolled off of the stick onto the cap and then the stick removed and the end of a fuse inserted into the cap and the protector unrolled so as to cover the adjacent end portions of the cap and fuse. 1

These devices have been used extensively for many years, but largely, if not entirely, by men with long experience with explosives and thoroughly familiar with the proper handling of the sticks and the detbnator caps. At the present time, and largely because of military operations, service men in the Army and Navy and other armed forces engaged in demolition work and having little or no experience are having occasion to attach fuses to detonating caps and, if they do not exercise caution, are likely to insert either end of the stick, mounting the fuse protectors, into the cap so abruptly or with such pressure that a premature explosion may result with disastrous results, or they may insert the wrong end of the stick into the cap and encounter diiculty in getting the protector ontovthe cap and back onto the inserted fuse. The likelihood of such objectionable resultsis enhanced if the opera# tions are performed in the dark or in great haste, as is frequently required in demolition work in modern warfare.

'Ihe main object of the invention is to prevent such untoward handling of the 'equipment'as disclosed in the above-mentioned patents.

In the manufacture of the rolled rubber tube devices shown in the above-mentioned Miller patents, it has been customary to load the fuse protectors onto the carrying stick at the factory by a separate loading needle" or formen usually made of metal, and it is a further object of the present invention to avoidv the necessity of using such a tool to load the sticks, and I accomplish this object by constructing the sticks so that the protectors, in tubular form, may be placed directly upon the sticks and rolled into the doughnut form.

These and other detail objects are attained by the structure illustrated in the accompanying drawing, in Which- Figure 1 is in part an elevation and in part a longitudinal sectionillustrating a typical stick or spindle upon which a plurality of protectors are carried in doughnut form ready for application to detonating caps. The right hand end of the figure illustrates the application of one of the protectors, in tubular form, to the stick.

Figure 2 shows the stick with its discharge end about to be inserted into a blasting cap and with a safety device yapplied to its loading end to prevent the insertion of the same into the blasting cap and to guard against the unrolling of the fuse protector over the loading end.

Figure 3 shows the stick applied to the blasting cap and one of the protectors rolled onto the cap.

Figure 4 shows the blasting cap With the protector stick removed and a length of fuse inserted into the open end of the cap.

Figure 5 shows the` protector unrolled into functioning position.

Figure 6 illustrates a modied form of protector mounting stick in which the loaded end is equipped with a different type of safety element and the stick is aranged to be loaded by a separate too1.

Figures 7, 8 and 9 correspond to the right hand end of Figure 6 but illustrate other forms of safety elements applied to the sticks.

The stick or spindle shown in Figures 1, 2 and 3 may consist of wood, plastic or other Suitable material and comprises an elongated body portion I having a diameter aproximating that of the fuse and blasting cap for which the protectors are intended to be used, 1A for example, The right hand end portion 2 of the stick tapers graduallyV to an end of substantially smaller diameter, 1/8 for example, facilitating its insertion intoa length of rubber tubing 3 comprising'the fuse protector. A section 4 of the stick preferably, but not necessarily, is threaded or grooved orotherwise roughened to more eiiectively resist the sliding ofthe section of tubing .along the same and thereby facilitate the rolling or coiling of the protector from the tubular form to the doughnut formjndicated at 5. When the protector has been rolled up, as indicated at 5, it may be rolled over and over along the stick without changing its general form. A large number of successive protectors may thus be mounted upon the stick, as indicated at 6.

The left hand end portion l of the stick is gradually enlarged to a diameter exceeding the inner diameter of the blasting cap 8 to which the protector is to be applied. A tip 9 of smaller diameter projects from the enlarged diameter portion 'I and is of reduced diameter to adapt it to be inserted into the open end of the blasting cap, as' shown in Figure 3. A shoulder I between parts I and abuts the end of the cap and limits the insertion of the stick into the cap so that tip SI will not contact the explosive material in the cap.` (Such caps are manufactured under Speciilcation-s which provide for a minimum clearance, 75" for example, between the explosive and the open end of the cap.)

After the st ick and cap have been assembled, as shown in Figure 3, the protector nearest the cap is rolled over and over the stick onto the cap to the position indicated at II `(Figure 3). Then the stick is removed and the -end portion of a fuse I2 is inserted in the cap (see Figure 4) and the fuse protector is unrolled so that it surrounds the cap for approximately half of its length and surrounds the fuse for the other half of its length, as shown at I3 in Figure 5. 'Ihis completes the step of connecting the fuse to the cap and waterproofing the joint so that it will not be affected by jarring, or the weather, and may even be placed under water.

It will be understood that the stick is loaded with a plurality of protectors at a factory or some other point remote from where the protectors are applied, one by one, to blasting caps and fuses and that each stick, with its load of fuse protectors, comprises a unit of manufacture which is carried by the operator and is ready for instant use as the occasion arises.

When the plurality of fuses are rst loaded on the stick, as indicated in Figures 1 and 2, it is desired to apply a safety element to the stick, and one form of such element isshown at I4 in Figures 2 and 3. Element I4 comprises a troughlike clip of relatively soft metal adapted to be applied to the end of the stick and secured thereto by deforming it, and to this end a portion of the member consists of relatively narrow ngers I5 which may be readily compressed about the stick, or even forced into the surface of the stick, so as to more securely hold the element to the stick. Element I4 will project laterally of the stick far enough to prevent the insertion of the loading end of the stick into a, blasting cap. Also the lateral projection of the element will check the unrolling of one of the fuse protectors from the loading end of the stick, even if the operator should start such an unrolling movement needless of the pronounced difference in the appearance and feel of the two ends of the stick.

Figure 6 illustrates another form of the invention in which the loading end of the stick is the same diameter as the body of the stick which mounts the protectors 2l. To facilitate the loading of the protectors onto a stickr of thistype, there is provided a loading tool indicated at 22 and corresponding generally to that shown in the above-mentioned Miller Patent 931,454.

The loading end of the stick is provided with a transverse aperture into which a key-like ele` ment 23 is inserted to prevent the return movement of the protector and to prevent the insertion of the loaded end of the protector into a blasting cap. The key may be tapered, as shown, and retained by driving it to a tight lit to set up suicient friction to resist its removal or it may be secured by glue, cement or, if necessary,.a transverse holding pin.

The discharge end 24 of the stick is shaped and shouldered the same as the loading end of the stick previously described.

Figure 7 illustrates another form of safety element comprising a nut-like member 30 screwed onto the stick 3|. The stick may be threaded to receive the nut or, if the nut is of substantially harder material than the stick, it may cut its own threads in the stickV as it is threaded onto the same or the elements may be free of threads but retained by frictional t or by glue.

Figure 8 illustrates another form of the invention in which the stick 32 is provided with a transverse passage and a Wire key 33 is inserted through the passage and is bent-around the stick so as to prevent its withdrawal.

Figure 9 illustrates another form of the invention in which a clip 34 is provided with elongated iingers adapted to be slid over the stick 35 and to frictionally engage the same or to bite into the same to prevent its withdrawal. This clip may comprise a cylindrical cup and may be secured by glue or otherwise.

Other forms of safety elements Will occur to those familiar with devices of this nature, and I contemplate the exclusive use of such modiiications of the safety .element or other changes in the details of the structure which do not depart from the spirit of the invention and come within the scope of the claims.

What is claimed is:

l. As a new article of manufacture, an elongated spindle, a plurality of separate fuse protectors mounted thereon for application one after the other to individual detonator caps, each of Which-protectors consists of a length of rubber tubing rolled onto the spindle in doughnut form, the spindle having a loading end, onto which the fuse protectors may be rolledyand having a discharge end, from which the fuse protectors may be rolled onto a detonator cap, the discharge end of the spindle including a part of greater diameter than the cap, and an element extending transversely of the spindle to a greater extent than the diameter of the cap and positioned so close to the loading end as to prevent accidental insertion of the loading end of the spindle into a cap into contact with the explosive in the cap.

2. A device as described in claim l in which the loading end portion of the spindle has a transverse aperture and the transversely extending element comprises a key insertible through the aperture and adapted to be retained therein and to extend beyond the periphery of the spindle.

3. A device as described in claim 1 in which the transversely extending element comprises a clip into which the loading end of the spindle may be inserted and readily secured.

4. A device as described in claim l in which the transversely extending element comprises a member with ngers bendable about the spindle to retain the member in place thereon.

5. As a new article of manufacture, an elongated spindle, a plurality of separate fuse protectors mounted thereon for application one after the other to individual detonator caps, each of which protectors consists of a length of rubber tubing rolled onto the spindle in doughnut form,

the spindle being of Wood corresponding in diameter to the diameter of the fuse to which the protectors are to be applied, said body having a portion near one end enlarged in diameter, to feed the protectors over a detonator cap, a short tip of reduced diameter projecting lengthwise from said end for insertion into the open end of the cap, there being a shoulder between the tip and the enlarged diameter portion to limit the insertion of the spindle into the cap, the other end portion of the spindle being tapered for ready insertion into an unrolled tubular protector, and a separately formed stop element secured to the tapered portion so near the end thereof, and projecting far enough laterally therefrom, as to prevent the accidental insertion of the tapered end portion into a cap and into contact with explosive therein said stop element comprising a trough-like structure of metal and having fingers With ends impressed in the Wooden spindle to maintain their 20 assembly.

6. As an article of manufacture, an elongated stick cylindrical substantially from end to end With a plurality of rubber tubes rolled up separately onto the stick from one end and adapted to be rolled off separately from the other end of the stick onto successive detonator caps of substantially the same diameter as the stick, one end of the stick having a tip of reduced diameter receivable in the open end 0f the cap, the tip end\ being shouldered to limit the extent of its insertion into the cap and the other end of the stick being provided with a lateral projection preventing its insertion into the cap.

7. A device as described in claim 1 in which the spindle is formed of wood and in which the transversely extending element comprises a troughlike structure of bendable material having fingers With tips imbedded in the wooden spindle.

JOHN S. CURTISS. 

